Punch means



April 24,1945'. R. KENNEDY ET AL PUNCH MEANS Filed July 8, 1943 Chor'les H.Bodner By.

Patented Apr. 24, 1945 NT N OFFICE PUNCHMEANS vRoi Kennedy, Los Angeles, William H. D. Hough, t i Glendale, and Charles H. Bodner, Los Angeles,` Calif., assignors, by mesne assignments', to` Lockheed Aircraft Corporation, a corporation of California Application July e, 1943, serial No. 493,810

7 Claims. (Cl. 164-118) This invention relates to punching apparatusl and relates more particularly to tools for punching openings `in sheetmaterial and the like. A general object `oi? the'invent'iongs to provide a simple, practical and very eiiective means for simultaneously forming a plurality of openings in sheet stock, plates, etc.

- In the mass production of sheet objects requiring the provision of accurately located openings it has been the common practice to drill the openings. The drill breakage is very high, particularly where small or relatively small openings are drilled in tough materials. Furthermore, the drilling operation produces burrs that must` be removed in a subsequent operation to condition the objects or parts for fabrication. y Another object of the invention `is to provide a punch operable to form openings in tough materials without leaving burrs and without the breakage of parts. l

Another object of the invention is to provide a punch or tool operable to simultaneously punch a plurality of accurately located burrless openings in tough resilient material in a single operation and without distortion of the work. f K

Another object of the invention is to provide artool of the character mentioned embodying a simple, `very eiective` stripper `means, assuring the formation of clean, burrless openings without distorting the Work piece even after extended use of the tool.

A further object of the invention is to provide a small, compact conveniently operated power punch for simultaneously forming burrless open-v ings in plate or sheet parts.

Other objects and features of the invention will be better understood from the following de#- tailed description of typical, preferred forms of the invention throughout which description ref` erence is made to the accompanying drawing in which:

Figure 1 is a side elevation of a pneumatic tool embodying `one form of the invention with the principal parts' appearing inl vertical cross section? y y Figure 2A is an enlarged' fragmentary vertical detailed sectional view ofthe active parts of the tool shownin Figure 1, being a view takenin a t plane at right angles to the plane of sectioning of cated thereby.

of the upper assembly of another form of the invention and, y

Figure 4 is an `enlarged 4fragmentary vertical sectional View of the apparatuslillustrated in Fig- `ure3.`

.l In Figures l, 2 and`2A ofthe drawing we have illustrated the invention embodied in a punch operable ,to simultaneously form spaced openings in a piece` of work. lThe particular embodiment of the invention shown in Figures 12 andZA is intended to form two spaced "openings in a plate nut, it being apparent that the invention may be adapted to other uses; `'Iohevtool of Figures l, 2 and 2A Vcomprises generally a pneumatic tool in the form of a small riveter l0, a yoke` llattached to the riveter I, and a punch assembly I2 in' the yoke `operated by the riVeter. o

The riveter I may beni o conventional con- Astruction and its detailsform nonpart of the present invention except insofar las they occur in combination with the `other elements of the invention.` It willbe sufficient to state thatthe pneumatic tool I0 has a downwardly projecting plungeror ram I3 that is operateddownwardly bypneumatic power and returned by a spring` I4.

The yoke I I is attached to a lower ilangel `of -the tool IIlby spaced bolts I6. The upper jaw II of the yoke II has a vertical opening I8 slidably passing the ram I3. The lower, jaw I9 of the 30 yoke I I is connected withtheupper jaw I1 by a web 20. I'he upper face of the lower jaw I9 carries a die plate 2l of hard material, the plate being attached to the jaw by spaced screws 22.` A locating pin 23 is replaceablyjsecuredin thelower jaw IS and extendsupwardly throughan opening in the die plate 2| to protrude beyondthe upper face of the plate. The work W is adapted to be engaged against the plate 2l and has an opening 24 for receiving the pin"23 to be accuratelylo- The punch assembly I2 includes what wewill term a punch hclder'25i The punch holder 25 is an elongate horizontally disposed member arranged at the under side ofjthe upper yoke jaw I'I. A socket 2E inthe'lupper side ofthe work holder 25 receives the lower portion of the pneumatic ram I3. A set` screw 2`Imay serve to x the holder 25 to the ram I3. Guide rods'28 are xed to lthe holder` 25` and project upwardly therefrom to slidablywoperate in openings f29 in the upper jaw Il. The guide rods'28 insure the correct movement'of the holder;- `A stripper plate 30 isprovided at the `'under side of the punch holder 25` and is" freely suspendedrtherefromby spaced screws 3I, y

The punch assembly I 2 further includes spaced punches 33. The punches 33 are engaged in openings in the holder and pass downwardly through openings 34 in the stripper plate 3l).

' The shanks of the punches have snug slip lits in the openings of the holder 25. Annular anges l 35 are provided on the punches 33 intermediate their ends and are engaged between the stripper plate and the under side of the holder 25. The

langes bear against the under side of the holder 25 to receive the downward thrusts therefrom and engage against the upper face of the plate 30. The bodies of the punches v33 are tapered at the under sides ofthe flanges 35 to present downwardly converging surfaces and the openings 34 of the stripper plate 30 are tapered or correspondingly shaped to receive the tapered parts. The portions of the punches 33 which project downwardly from vthe plate 30 are formed to punch openings of the selected diameter in the work W. The die plate 2| is provided with openings3l vertically aligned with the punches 33. The under parts` of these openings 31 are ilared or enlarged and communicate with openings 38 in y the lower jaw I9. The openings 38 are adapted to discharge theslugs or scrap pieces of metal punched from the work W .by the punches 33.

The invention is characterized by stripper blocks 40.A The stripper blocks are provided at the under side' of the stripper plate 30 and are thick walledtubular parts engaged about the downwardly projecting portions of the punches 33. .The blQCks are formed of a compressible resilient material such as rubber, rubber Compesiticn, or synthetic rubber. The upper ends of the stripper blocks 40 bear against the under side of the plate 3l] and the blocks are-proportioned to normally extend downwardly beyond the lower ends` of the punches 33. With the ram I3 n'ts.

raised position,` the lower ends `of the blocks 40 I are spaced above the die plate 2| so that the work W may be readily positioned on the die plate.

In the use or operation ofthe tool illustrated in Figures 1, Zand 2 A`the Work W is engaged'on the die platelZI sothat the pin 23 engages in its opening 24. The pneu-matic tool I0is then put into operation so that the ram I3 forcibly moves downwardly to actuate the punch assembly I2. The compressible blocks 40 rstcome into engagemerllil with, the Work W and the stripper plate 3.0. is in effect clamped between the blocks 40 and the flanges 35 of the punches. The skirts or flanges 35 of the punches are thus forced against the under face, of the punch holder 25 and this action serves to accurately align the punches with the openings 3,1 in the die plate 2 I. In this connection, it is to be understoodthat after extended usage the upper portions of the punches 33 may have limited movement in the openings of the holder 2.5, and the tapering portions of the punches operate in the tapered openings 34 of the stripper plate 3.0 to provide for the automatic aligning of the punches-33 as just described. By

the time the lower ends of the punches 33 engage the workW thepunches are accurately aligned with respectl tothe openings 3'I in the plate 2I.

A{I'hlf punches 313. pass through the work W to .punch or form the openings therein. In practice In Figures 3 and 4 we have illustrated thelin-[U vention embodied in a template pierce die that includes generally a lower plate assembly 50, an upper plate assembly 5Iy and punch means 52 on the upper assembly.

The lower plate assembly includes a base plate 53 of metal, a selected plastic or other suitable material. A die plate 54 of selected hard steel is secured to the upper face of the .base plate 53 by screws 55. Spaced openings 56 are provided in the die plate 54 in positions determinedby the particular work to be performed. Openings5l in the base plate 53 communicate with the die openings 56 and join channels or grooves 58 formed in the under side of the base plate 53. The openings 5l and the channels 58 serve to receive the slugs punched from the work W. Means is provided for locating the work W on the die plate 54; Any selected form of locating means may be employed, In the simple case illustrated locating pins 5Hv are securedin openings in the base plate 53- and have shouldered engagement in openings 66 in the `die plate 54. vReduced portions of the locating pins 56 project from the die plate- 54 and are adapted to extend through openings 6I in the Work W to accurately'locate the work,A

The upper assembly 5I includes an upper or outer 4plate 62 of plastic or other suitable material and a plate 63 of steel or the like secured tothe under side of the plate 62 by screws 64.-; The upper and lower assemblies 56 and 5I may correspond' in outline or conguration and means are provided for locating the die assemblies in the die set. In the case illustrated these locating means consist of aligned bushings 65 secured in openings in the edge portions of the base plate 53 and the outer plate 62. The die plate 54 and the plate 63 may have openings 66 communicating with the bushings 65.

The punch means 52 is provided on the under i,

side of the upper plate assembly 5I. The punch means includes a stripperanchor plate 61 spaced from the under side of theplate 63 and freely suspended therefrom by screws 68.= Spacers 68A may be provided on the screws between the plates 63 and 6.1. The punch means 5,2 further includes a plurality of punches 69.l The punches 69 may members provided betweentheir ends with annular flanges or skirts l0. The upperportions of the punches 69 tare slidably received in openings 'I I in the plate 63 and the plate 62 so that the upper faces of the skirts 1 0 may flatly bear against the under side of the plate 63. The punches 69 extend downwardly through openings 'I2 in theanchor plate 6'1. The surfaces of the' Shanks of the punches 6 9 curve or taper downwardly and inwardlyk from the under sides of the skirts 'I0 and `the openings. 'I2 are correspondingly tapered so vthat the punches may have limited rocking movevment under certain conditions of operatio'nll The punches 69 project downwardly lfrom theanchor plate 61 to cooperate withthe openings'Sy inthe die plate54 during the punching operation.. y

Stripping means are provided for the punches G9. Where thepunches 69 vare substantial distances apart, individual stripper b1ocks`13are provided on the individual punches. .Theblocks 'i3 may be similar to the above described 'blocks 4 0, being tubular, cylindrical members of Com-pressible, resilient material such as rubberjorsynthetic rubber. Where the punches V69; areinadjacent relati on, a single, stripper block "I'4ma`y be provided for the several adjacent punches.v Such blocks 14 are illustrated in Figure 3 and in this case they are elongate members having spaced openings 15 for receiving the active cutting portions of the punches. The upper ends of the stripper blocks 13 and 14 bear against themunder surface ofthe anchor plate 61 and the blocks may extend below the idlepunches.

In use the work W is arranged on the die plate 54 to be accurately located by the engagement of the locating pins 59 in the openings 6l. When the die set is operated the stripper blocks 'I3 and 'I4 rst come into engagementwith the work W and are compressed. The punches 61` are forced Having described only typical forms of the in-` vention, we do not wish to be limited to the speciflc details herein set forth, but wish to reserve to ourselves any variations ormodifications that may appear to those skilled in the art or fall within the scope of the following claims.

We claim:

l. .In punch means, a die part having an opening, a second part, one part being movable toward the other, an anchor member movable with and hung from said second part, the anchor-member and said second part having openings aligned with the rst named openings, a punch received in the second named openings and projecting `from said member to punch an opening in work` on the die part upon movement of one part toward the other, and an annular skirt on the punch engaged between said member and said second part` and cooperating therewith to constitute the sole means for holding the punch against axial movement whereby the engagement of `the skirt with said second part serves to position the punch.

2. In punch means, a die plate having an opening, a part movable toward the die plate, an

anchor member `suspended from said part and ,portion in said second named opening allowing the punch to rock so the engagement of the` flange with said part brings the second named portion of the punch into alignmentywith the opening of the die plate. l

3. In punch means, a die plate having an opening, a part movable toward the die plate, an anchor member secured to said part to be in spaced relation thereto and having atapered opening aligned with the first named, opening, a punch having a tapered portion tiltably engaged in the second named opening` and a portion projecting toward the die plate toipunch an opening in the Work on the dieplate upon movement of said part toward the die plate, a flange on the punch between said part and the anchor member adapted to 'be forced against said part to tilt the punch to bring its second named portion into alignment with the opening `in the die part, and aicompressible resilient stripper on the project- `ing portion of the punch compressed between the Work and said member during the punching action to strip the punch and to cause said member to `force said nange evenly against said part.

4. In punch means, a die plate on which the work is arranged and having an opening, a part movable toward Vthe die plate and having a flat `face opposing the die plate, a member secured to said part and spaced from said face, the member having a tapered opening aligned with the first` named opening, a punch having a tapered portion movably engaged in the tapered opening and-,a cutting portion projecting from said member to punch` an opening in the work upon movement of said part toward the `die plate, and a ange on the punch between said part `and member having a face to` move said tapered portion in the tapered opening to bring said cutting portion intoalignment with the iirst named opening for flatly beari compression assuring the flat engagement of the ing on the rst named face.

` 5. In punch means, adie plate on which the work is arranged and having spaced openings, `a l named openings, punches having tapered portions movably` engaged in said openings and cutting portions projecting toward the `work to punch openings therein upon movement of said part toward the die plate, flanges on the punches adaptedto come into even engagement with said face to align the 'punches with the rstnamed openings, and stripper elements around said cutting portions compressed between said `member and work `during the punching operation, said ilanges with said face to align the punches with said first named openings.

6. In punch means, a die plate on which the work is arrangedand having spaced openings, a` part movable toward the die plate and. having a at face opposing the same, a membersuspended froml said part and spaced from said face, the member having tapered openings aligned with the rst named openings, punches having tapered portions movably engaged in said openings and `cutting portions projecting toward the work to punch openings therein' upon movement of `said part toward the die plate, flanges on the punches adapted to flatly bear on said'face to align the i punches with the rst` named openings, and a block of compressible resilient material having openings receiving the several cutting portions and compressed between said member and the work to cause said :anges to flatly engage said face and to strip the punches.

'7. In punch means, a part presenting a at surface, a member carried by said part and presenting a face spaced from and opposing said flat sur- 55 bearing on the rst named surface to accurately l align the' punch and a portion `joining the ange 

